Only sysvcompat and sysvinit should conflict, allowing initscripts and sysvcompat to be installed at the same time (this is done, but the conflict still exists in the package)

Merge locale.sh from initscripts/sysvcompat to systemd? Look for an alternative solution to setting locale at login?

Split off some of the tools from sysvinit (pidof, last, ...) into sysvinit-tools, which initscripts should depend on

sysvcompat should then provide sysvinit, to resolve the dependency issue

Make sure timedated's managing of NTP works

Add files to ntpd, chrony, openntpd for /usr/lib/systemd/ntp-units.d

Packaging notes

Units

Use the upstream unit files whenever they exist

Try not to do anything Arch-specific. This will maximize chances of not having to change behavior in the future once the unit files are provided by upstream. In particular avoid EnvironmentFile=, especially if it points to the Arch-specific /etc/conf.d

Always separate initialization behavior from the actual daemon behavior. If necessary, use a separate unit for the initialization, blocked on a ConditionFoo from systemd.unit(5). An example of this is sshd.service and sshdgenkeys.service.

Not using an EnvironmentFile= is OK if:

Either the daemon has its own configuration file where the same settings can be specified

The default service file "just works" in the most common case. Users who want to change the behavior should then override the default service file. If it is not possible to provide a sane default service file, it should be discussed on a case-by-case basis

A few comments about service files, assuming current behavior should be roughly preserved, and fancy behavior avoided:

If your service requires the network to be configured before it starts, use After=network.target. Do not use Wants=network.target or Requires=network.target

Use Type=forking, unless you know it's not necessary

Many daemons use the exit of the first process to signal that they are ready, so to minimize problems, it is safest to use this mode

To make sure that systemd is able to figure out which process is the main process, tell the daemon to write a pidfile and point systemd to it using PIDFile=

If the daemon in question is dbus-activated, socket-activated, or specifically supports Type=notify, that's a different matter, but currently only the case for a minority of daemons

Arch's rc scripts do not support dependencies, but with systemd they should be added add where necessary

The most typical case is that A requires the service B to be running before A is started. In that case add Requires=B and After=B to A.

Note: Keep in mind that values to keys such as ExecStart and ExecStop are not run within a shell, but only passed to execv

tmpfiles.d

Instead of creating necessary runtime directories and files when a service is started (as some rc scripts do), ship a tmpfiles.d(5) config file in /usr/lib/tmpfiles.d.

Add a line systemd-tmpfiles --create foo.conf to post_install (and post_upgrade if needed) to ensure the necessary runtime files are created on install, not just on the next boot

Tip: This feature can be used for a whole lot of other things, e.g. for writing to arbitrary files, even in /sys

modules-load.d

Instead of loading necessary modules when a service is started (as some rc scripts do), ship a modules-load.d(5) config file in /usr/lib/modules-load.d.

Add modprobe lines to post_install (and post_upgrade if needed) to ensure the necessary modules are loaded on install, not just on the next boot

ntp-units.d

For NTP daemons, systemd-timedated requires an additional file in /usr/lib/systemd/ntp-units.d. It should be named after the package it belongs to (with a .list suffix), and contain the name of the service which starts the NTP daemon itself.

sysctl.d

IMO(dreisner): This should generally be avoided, as tying low level kernel behavior to a package might be considered evil.